Arno Frigg

Chronische Instabilität des oberen Sprunggelenks

ZusammenfassungDie chronische Sprunggelenkinstabilität ist eine typische Pathologie im Sport und entwickelt sich bei 20 bis 40% der Sportler nach erlittener akuter Sprunggelenkdistorsion. Man unterscheidet zwischen einer lateralen und medialen Sprunggelenkinstabilität, wobei die Kombination beider als Rotationsinstabilität des oberen Sprunggelenks bezeichnet wird. Des Weiteren kann pathophysiologisch eine mechanische oder funktionelle Sprunggelenkinstabilität unterschieden werden, die sich durch eine strukturelle Bandläsion bzw. durch eine Schwächung der neuromuskulären Kontrolle manifestiert. Durch die erschwerte Diagnose und eine komplexe Therapie, die oft eine operative Rekonstruktion bedingt, stellt die chronische Sprunggelenkinstabilität für den behandelnden Arzt eine vielschichtige Entität dar. Die vorliegende Übersichtsarbeit erörtert Pathomechanismen, Möglichkeiten der Diagnostik, Indikationen zur konservativen und operativen Therapie sowie potenzielle Langzeitschäden wie die posttraumatisch-ligamentäre Sprunggelenksarthrose.AbstractChronic ankle instability represents a typical sports injury. After an acute ankle sprain 20-40% of the injured develop chronic ankle instability. From an orthopaedic point of view chronic ankle instability can be subdivided into lateral and medial instability or a combination of both, the so-called rotational ankle instability. From a pathophysiological point of view, chronic ankle instability can be either mechanical with a structural ligament lesion or functional with loss of neuromuscular control. For the physician chronic ankle instability is a difficult entity as the diagnosis is usually complex and the therapy often surgical. This review on chronic ankle instability deals with the pathomechanisms, diagnostics, indications for conservative and surgical treatments, and possible long-term sequelae, such as ligamentous osteoarthritis.

The effect of osseous ankle configuration on chronic ankle instability

Background: Chronic ankle instability (CAI) is a common orthopaedic entity in sport. Although other risk factors have been studied extensively, little is known about how it is influenced by the osseous joint configuration. Aim: To study the effect of osseous ankle configuration on CAI. Design: Case–control study, level III. Setting: Radiological examination with measurement of lateral x rays by an independent radiologist using a digital DICOM/PACS system. Patients: A group of 52 patients who had had at least three recurrent sprains was compared with an age-matched and sex-matched control group of 52 healthy subjects. Main outcome measures: The radius of the talar surface, the tibial coverage of the talus (tibiotalar sector) and the height of the talar body were measured. Results: The talar radius was found to be larger in patients with CAI (21.2 (2.4) mm) than in controls (17.7 (1.9) mm; p<0.001, power >95%). The tibiotalar sector, representing the tibial coverage of the talus, was smaller in patients with CAI (80° (5.1°)) than in controls (88.4° (7.2°); p<0.001, power >95%). No significant difference was observed in the height of the talar body between patients with CAI (28.8 (2.6) mm) and controls (27.5 (4.0) mm; p = 0.055). Conclusion: CAI is associated with an unstable osseous joint configuration characterised by a larger radius of the talus and a smaller tibiotalar sector. There is evidence that a higher talus might also play some part, particularly in women.

Clinical relevance of hindfoot alignment view in total ankle replacement.

Background: Alignment is instrumental for success and long-term survival of Total Ankle Replacement (TAR). At this point in TAR, only coronal alignment in the region of the tibiotalar joint or above has been assessed because inframalleolar deformity is difficult to visualize radiographically. The Hindfoot Alignment View (HAV) allows visualization of the hindfoot position relative to the tibia. The purpose of this study was to evaluate the clinical relevance of this view in assessing patients with TAR. Materials and Methods: Twenty-eight consecutive patients with a Hintegra-TAR with an average followup of 4.1 ± 1.5 years were followed with (1) AOFAS and SF-36 scores, (2) visual judgment of the hindfoot position, (3) HAV and AP/lateral radiographs, (4) dynamic pedobarography (Novel emed m/E, Munich, Germany). Results: The HAV position correlated well with different load parameters on heel strike (r = 0.44 to 0.62) but not with the varus-valgus load pattern of the rest of the foot. Visual judgment and TAR joint line did not correlate to radiographic hindfoot alignment or to pedobarographic load distribution. The hindfoot alignment measured by the HAV correlated significantly to the Physical Function and Role Physical of SF-36. No correlation was found to other SF36-qualities or the AOFAS-score. Conclusion: Inframalleolar alignment, as assessed by the HAV, influenced the dynamic pedobarographic load pattern and clinical outcome. Visual judgment and TAR joint line were not accurate enough to estimate the hindfoot alignment or dynamic load pattern. We believe adjusting the hindfoot correctly with HAV might improve long-term outcome and survival of TAR. Level of Evidence: IV, Retrospective Case Series

Frontal and lateral characteristics of the osseous configuration in chronic ankle instability

Objective The osseous ankle configuration (tibiotalar sector, talar radius and height) has been discovered as intrinsic risk factor for chronic ankle instability (CAI). These measurements were done on lateral radiographs only. In this study, the osseous characteristics in the frontal plane and further lateral values were measured. Design Level III case-control study. Setting Radiological measurement of frontal and lateral radiographs by one independent, blinded radiologist using a digital DICOM/PACS system. Patients A group of 52 patients with CAI was compared with an age- and sex-matched control group of 52 healthy subjects. Main outcome measurements In the frontal plane, the depth of the talar curvature (frontal curvature (froCu)) and the lateral and medial malleolar lengths were measured. In the lateral plane, the position of the centre of rotation to the tibial axis (talar centre of rotation to the anatomical axis of the tibia (TibCOR)) and the tibial lateral surface angle (TLS) were also measured. Results The froCu was deeper in patients with CAI (1.8 (0.5) mm) than in healthy subjects (1.0 (0.5) mm, p<0.05). The TibCOR was more anterior in patients with CAI (2.5 (1.9) mm) than in healthy subjects (1.6 (2.2) mm, p<0.05). The distance from the fibular tip to the centre of rotation was smaller in patients with CAI (3.5 (3.4) mm) than in healthy subjects (6.5 (3.3) mm, p<0.05). The TLS and the length of the lateral and medial ankle were not significantly different. Conclusions This study supports that the osseous joint configuration is an intrinsic risk factor for CAI. It could be shown that CAI is characterised by a deeper frontal curvature of the talus and a more anterior position of the talus to the tibia.

Direkte anatomische Rekonstruktion des lateralen Bandapparats bei chronischer lateraler Instabilität des oberen Sprunggelenks

F Chronische laterale Sprunggelenksinstabilität mit rezidivierenden lateralen Distorsionsereignissen des oberen Sprunggelenks (OSG), F Versagen einer extensiven konservativen Therapie, F Reduktion der Sportfähigkeit und Lebensqualität, F pathologischer Schubladentest und lateraler Aufklappbarkeitstest, F arthroskopisch nachgewiesene pathologische laterale OSG-Aufklappbarkeit, F elongierte oder rupturierte laterale OSG-Ligamente mit genügend ortständigem Bandmaterial.

Direct anatomic repair of the lateral ankle ligaments in chronic lateral ankle instability

F Chronische laterale Sprunggelenksinstabilität mit rezidivierenden lateralen Distorsionsereignissen des oberen Sprunggelenks (OSG), F Versagen einer extensiven konservativen Therapie, F Reduktion der Sportfähigkeit und Lebensqualität, F pathologischer Schubladentest und lateraler Aufklappbarkeitstest, F arthroskopisch nachgewiesene pathologische laterale OSG-Aufklappbarkeit, F elongierte oder rupturierte laterale OSG-Ligamente mit genügend ortständigem Bandmaterial.

Intraoperative Positioning of the Hindfoot With the Hindfoot Alignment Guide A Pilot Study

Background: In a previous study, intraoperative positioning of the hindfoot by visual means resulted in the wrong varus/valgus position by 8 degrees and a relatively large standard deviation of 8 degrees. Thus, new intraoperative means are needed to improve the precision of hindfoot surgery. We therefore sought a hindfoot alignment guide that would be as simple as the alignment guides used in total knee arthroplasty. Methods: A novel hindfoot alignment guide (HA guide) has been developed that projects the mechanical axis from the tibia down to the heel. The HA guide enables the positioning of the hindfoot in the desired varus/valgus position and in plantigrade position in the lateral plane. The HA guide was used intraoperatively from May through November 2011 in 11 complex patients with simultaneous correction of the supramalleolar, tibiotalar, and inframalleolar alignment. Pre- and postoperative Saltzman views were taken and the position was measured. Results: The HA guide significantly improved the intraoperative positioning compared with visual means: The accuracy with the HA guide was 4.5 ± 5.1 degrees (mean ± standard deviation) and without the HA guide 9.4 ± 5.5 degrees (P < .05). In 7 of 11 patients, the preoperative plan was changed because of the HA guide (2 avoided osteotomies, 5 additional osteotomies). Conclusions: The HA guide helped to position the hindfoot intraoperatively with greater precision than visual means. The HA guide was especially useful for multilevel corrections in which the need for and the amount of a simultaneous osteotomy had to be evaluated intraoperatively. Level of Evidence: Level IV, case series.

Survival of the Scandinavian Total Ankle Replacement (STAR): Results of Ten to Nineteen Years Follow-up

Category: Ankle Arthritis Introduction/Purpose: The purpose of this study was to evaluate survival and clinical outcome of the Scandinavian total ankle replacement (STAR) prosthesis after a minimum of ten years up to a maximum of 19 years. Methods: Fifty STAR prostheses in 46 patients with end stage ankle osteoarthritis operated between 1996 and 2006 by the same surgeon (MH) were included. Minimal follow-up was ten years (median 14.6 years, 95% confidence interval [CI] 12.9-16.4). Clinical (Kofoed score) and radiological assessments were taken before the operation and at one, ten (+2), and 16 (±3) years after implantation. The primary endpoint was defined as exchange of the whole prosthesis or conversion to arthrodesis (def. 1), exchange of at least one metallic component (def. 2), or exchange of any component including the inlay (due to breakage or wear) (def. 3). Survival was estimated according to Kaplan-Meier. Further reoperations related to STAR were also recorded. Results: The ten year survival rate was (def. 1) 94% (CI 82- 98%), (def. 2) 90% (CI, 77-96%), and (def. 3) 78% (CI 64-87%). The 19-year survival rate was (def. 1) 91% (CI 78-97%), (def. 2) 75% (CI 53-88%), and (def. 3) 55% (CI 34-71%). Considering any re-operations related to STAR, 52% (26/50) of prostheses were affected by re-operations. Mean pre-operative Kofoed score was 49, which improved to 84 after one year (n = 50), to 90 after ten years (n = 46), and to 89 after 16 years (n = 28). Conclusion: The survival rate for def. 1 and 2 was high. However, re-operations occurred in 52% of all STAR prosthesis.

Radiographic Study of Pes Planovarus

Background: Depending on the direction of the subtalar joint, a foot deformity generally tends towards pronation (pes planovalgus) or supination (pes cavovarus). However, the combination of hindfoot varus and flat midfoot/forefoot (pes planovarus) is an exception to this rule. Pes planovarus has so far only been referred to in connection with Müller-Weiss disease and congenital disease. We diagnosed pes planovarus in otherwise healthy patients without these diseases. Methods: Forty patients with 54 symptomatic feet who were treated between August 2012 and July 2016 were included (mean age, 44.1 ± 15.7 years; 15 male/25 female). They were selected from 1064 consecutive cases (3.8%). Inclusion criteria were hindfoot varus and flat midfoot/forefoot. Their symptoms, radiographs, and therapies within the first 3 months were retrospectively analyzed. The position in the hindfoot alignment view (HAV), talometatarsal-1 angle lateral (TMT1lat) and dorsoplantar (TMT1dp), talocalcaneal angle lateral (TCAlat) and dorsoplantar (TCAdp), and calcaneal pitch angle (CPA) were measured on a DICOM/PACS system. Results: The mean radiological results (standard values from the literature in brackets) were as follows: the hindfoot was significantly in varus in the HAV (−6.9 ± 3.6 mm [−1.6 ± 7.2 mm]; P < .001), the TMT1lat was significantly flatter (−6.7 ± 5.8 degrees [8.4 ± 5.9 degrees]; P < .001), the TMT1dp was significantly less in abduction (1.5 ± 7.9 degrees [7.7 ± 8.2 degrees]; P = .005), the TCAdp showed no difference (25.9 ± 7.9 degrees [24.1 ± 5.7 degrees]; P = .118), the TCAlat was significantly larger (47.5 ± 6.1 degrees [43.4 ± 7.1 degrees]; P < .001), and the CPA was significantly flatter (17.6 ± 3.9 degrees [24.5 ± 3.0 degrees]; P < .001). The most frequent symptoms were stress-induced foot pain (n = 33), hallux valgus (n = 20), chronic ankle instability (n = 17), metatarsalgia (n = 15), chronic midfoot pain (n = 13), heel pain (n = 12), and lesser toe deformities (n = 8). Thirty-one feet were treated conservatively and 23 operatively. Conclusion: This study showed the existence of pes planovarus without Müller-Weiss disease or congenital disease. This unusual foot form leads to difficulties if standard treatment strategies are applied, which raises the issue of the correct treatment for such patients. Level of Evidence: Level IV, retrospective case series.

Direkte anatomische Rekonstruktion des lateralen Bandapparats bei chronischer lateraler Instabilität des oberen Sprunggelenks@@@Direct anatomic repair of the lateral ankle ligaments in chronic lateral ankle instability

F Chronische laterale Sprunggelenksinstabilität mit rezidivierenden lateralen Distorsionsereignissen des oberen Sprunggelenks (OSG), F Versagen einer extensiven konservativen Therapie, F Reduktion der Sportfähigkeit und Lebensqualität, F pathologischer Schubladentest und lateraler Aufklappbarkeitstest, F arthroskopisch nachgewiesene pathologische laterale OSG-Aufklappbarkeit, F elongierte oder rupturierte laterale OSG-Ligamente mit genügend ortständigem Bandmaterial.